I see, well, thanks for the answers! It's a shame they didn't go through with the idea of having direct cooperative in the same country, this is one of the few games where that idea would actually work well, in my opinion:
In a regular RTS game, one player would be playing a super unit, although it would most likely still be pretty generic in being a tank or aircraft, whereas this game's unit is unique enough to be interesting. It brings back a Battle Engine Aquila / Ace Combat / Lair vibe where you are contributing to a large battle, but this time it would have been the battle of the commander who is focusing on standard RTS gameplay, making you feel like their secret weapon among their forces. I'm sure there is a niche for that among cooperative players, as both the RTS commander and dragon benefit from being micromanaged more than switching between them could easily do.
I do admit that some of the old concerns such as one player becoming bored with the dragon was possible, but it might have been remedied by allowing shared RTS control with the option of one of them becoming the dragon if needed, otherwise a small group of units could be micromanaged which is one of the benefits of sharing control of an army, especially on harder difficulties with worse odds.
Finally, I haven't played the game so I can't be sure of 4 player RTS battles where everyone is an enemy, but if so and this feature had been added, there could have been eight players participating in battle at once, four strategic masterminds vying for control with a spectacular and constant dragon battle going on overhead - it might have been epic to feel you have a champion fighting for air superiority. I fear this idea wasn't given much praise when it was being pitched because it would be less effective in general multiplayer, but I'm sure of there being groups of people who seek grand coop-competitive gameplay within friend circles, or even in battles organised from groups, myself being one of them.
All the same, still an excellent game with some definitely unique ideas. Thanks for the speedy response